The present invention relates to fluid oscillators and nozzles demanding structural and operating constraints. Such constraints include extremely small size, relatively high flow rates, low head loss, low oscillation frequencies, and waveforms that produce relatively even flow distributions over the output sweep area--all to achieve high efficiency and efficacy in use and application of the moving fluid. Such uses include cooling, heating, wetting, drying, washing, cleaning, rinsing, and scaling; application of chemicals, paints, adhesives, insecticides, and the like; the stimulation of body surfaces, tissues, and of blood circulation; the debridement of wounds; the dispersal of liquids into gases and vice versa; and, the mixing of gases and liquids.
Various fluid oscillators are known to be usable for some of the tasks mentioned above, but they have not been able to approach the extreme criteria required by devices of the present invention--particularly concerning the properties of small size, low head loss and high flow rates, while operating at relatively low frequencies with high efficiency and efficacy. Some prior fluid oscillators which, under much relaxed criteria and requirements, might be usable for some of the above-mentioned tasks, albeit not as advantageously as the devices of the present invention, are described in such U.S. patents as U.S. Pat. Nos. 4,052,002; 4,231,519; and, 4,184,636.
Various limitations of such prior fluid oscillators have often precluded their successful use in many applications. For instance, physical size requirements inherent in many product applications disallowed use of conventional oscillators since they could not provide sufficient flow within the spatial constraints. Similarly, performance of the output streams or spray from prior oscillators was often degraded due to relatively high head losses. In some product applications with small size criteria, for instance, oscillation frequency is required to be relatively low, but, in general, the smaller the oscillator size, the higher its frequency. Hence, suitably-sized oscillators have often been unable to provide slow enough oscillations.
Accordingly, it is an object of the present invention to provide a fluid oscillator having hitherto unattainable combinations of advantageous properties, such as extremely small size and relatively low frequencies, together with high flow rates and low head loss.
Another object of the invention is to provide a miniature nozzle of the fluid oscillator type that is small enough to be suitable for use within a toothbrush; and, effective to wet bristles and to dispense water or appropriate chemical solutions over the brushed regions of teeth and gums, to help cleanse teeth and oral tissues, to flush out particles, and to stimulate blood circlation in oral tissues.